The current systems for controlling tools does not provide for total tool accountability. Total accountability requires that every tool have a place, every tool must be in its place, and for any tool that is not in its place a trail leads to the last authorized user of the tool and the task on which it was used. And if a lost tool is found, the exact location of its origin is known. For example, using currently available tool control systems, when a tool is found on an airplane, its origin cannot be positively identified. The tool may be identical to one that is missing from a tool kit at one air force base, but nonetheless, the tool could have been left on the plane while it was at an entirely different base. To overcome this, the Air Force, the Aerospace industry, and private industry is looking for a new system that will positively track and control every tool in its system. The tracking and control system should positively link each tool to a base and squadron, along with the kit's name, origin, and include a list of all the other components of the kit. Further, the last authorized user of the kit and the plane on which the tool was last used (Aircraft, Kit Number, Tool Number, Tool date of purchase, and variable local use information) should also be available.
Tool control is very important in the military and Aerospace industries. A tool left in the engine of an aircraft could damage the engine and perhaps the whole plane. A tool left in the engine compartment of a helicopter or on the space shuttle can have similar consequences. The danger becomes compounded during military exercises and missions when fighters returning from a mission must be refueled and rearmed within a minimum time and returned to combat. Technical Services personnel are expected to perform their tasks within predetermined time constraints so as not to delay the return of the plane to combat. The military and Aerospace Industry refer to damage caused by tools left on board military vehicles as “foreign object damage” or FOD/FOE. FOD/FOE Control is a high priority in the military/management issue. The Air Force uses the term TAS, which stands for “Tool Accountability System” for its program to control FOD and other branches of the military and certain industries of civilian commerce use other terms for dealing with the same problem.
The manufacturers of airplanes use manual and visual methods to track every tool that is used in the course of assembling or servicing a plane. If all the tools cannot be accounted for, the plane must be searched or possibly x-rayed before it is placed in service. The importance the Air Force's places on Tool Control is evidenced by the fact that it is a court martial offense the first time a technician leaves a tool on board an airplane without telling a Sergeant and therefore, every technician must know exactly what tools he has brought on board the airplane so he will know if any are missing.
It has become the practice to assemble tool kits with each tool kit containing the exact tools a technician would need to work on a specific air or space vehicle. For example, if an air force base has only two or three helicopters fitted for certain weapons systems, a number of tool kits will be specifically prepared for use by technicians working on those helicopters.
Currently, the tools are monitored by assembling them into a kit in which the tools are mounted on a vertical shadow board or are inserted into shadow boxes in the pockets of pallets or drawer inserts. Each shadow board, shadow box, pallet or insert has, at the point of retention of a tool, the silhouette of the tool to be retained. At the bottom of each pocket, or printed on each silhouette, is the description of the tool to be retained therein and the part number. The kits are kept in a controlled environment until they are assigned to a specific technician who is responsible for returning the kit with all the tools in each of the associated pockets therefore, inventory—tool in and out.
The technology is currently available to print information on any tool in a form that is readable with the human eye, however, space limitations on the surface of the tool limit the amount of information that can be visually readable. It is the practice to print the tool number on the tool using Arabic numbers and English letters, but the more detailed information about the tool such as the name of the base, the squadron number, and the kit number is rarely printed on the surface thereof.
Prior efforts to use a traditional bar scanner or computerized tracking and computer readable codes to monitor tools have not been successful for a number of reasons. Because of their functional nature, tools have surfaces, which in the past have been considered unsuitable for receiving the known methods of applying a conventional bar code of the type readable or scanable code by a computer. A linear bar code requires a flat surface and for some tools there are no flat surfaces suitable for receiving a conventional bar code. The material of which the tool is made is also functional and is generally unsuitable for receiving a conventional bar code. Prior to the present invention, there has been no suitable method for applying an electronically readable code to chrome, stainless steel, black oxide metal, coated steel, plastic, rubber, wood, or to a concave or a convex surface.
Chrome surfaces are applied to tools to protect the metal of which the tool is made from rust or other forms of deterioration. The chrome surface provides a function, which extends the useful life of the tool, but chrome is reflective and electronic codes applied to a chrome surface using existing technology are unreadable by a scanner because the scanner is unable to detect sufficient contrast between marked and unmarked portions of the surface. Black oxide surfaces are totally non-reflective and electronic codes applied to black oxide using existing technologies are also unreadable. Similarly, plastic, rubber, and wood are not suitable media for receiving readable electronic codes. It is also unsatisfactory to provide a label to be attached to the surface of a tool because there is a risk that the label itself may become detached from the tool and become a source of FOD.
It should be appreciated that a system employing an electronically readable coding is of little value to the military unless the system will operate with a very low incidence of failure. If wear of the type ordinarily suffered to the surface of a tool will render the electronic coding on the surface unreadable, the tool will not be identifiable when it is found on a plane and the system will have failed when it is needed most.